<template>
  <div class="home-page">
    <div class="banner">
      <div class="container">
        <h1 class="logo-font">是洋柿子啊</h1>
        <p>A persimmon tells you to learn English.</p>
      </div>
    </div>

    <div class="container page">
      <div class="row">
        <div class="col-md-9 box-height">
          <div class="feed-toggle">
            <ul class="nav nav-pills outline-active">
              <li v-if="user" class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'your_feed',
                  }"
                  exact
                  :to="{
                    name: 'home',
                    query: {
                      tab: 'your_feed',
                    },
                  }"
                  >Your Feed</nuxt-link
                >
              </li>
              <li class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'global_feed',
                  }"
                  exact
                  :to="{
                    name: 'home',
                  }"
                  >Global Feed</nuxt-link
                >
              </li>
              <li v-if="tag" class="nav-item">
                <nuxt-link
                  class="nav-link"
                  :class="{
                    active: tab === 'tag',
                  }"
                  exact
                  :to="{
                    name: 'home',
                    query: {
                      tab: 'tag',
                      tag: tag,
                    },
                  }"
                  ># {{ tag }}</nuxt-link
                >
              </li>
            </ul>
          </div>

          <div class="article-preview" v-for="article in articles" :key="article.slug">
            <div class="article-meta">
              <nuxt-link
                :to="{
                  name: 'profile',
                  params: {
                    username: article.author.username,
                  },
                }"
              >
                <img :src="article.author.image" />
              </nuxt-link>
              <div class="info">
                <nuxt-link
                  class="author"
                  :to="{
                    name: 'profile',
                    params: {
                      username: article.author.username,
                    },
                  }"
                >
                  {{ article.author.username }}
                </nuxt-link>
                <span class="date">{{ article.createdAt | date("MMM DD, YYYY") }}</span>
              </div>
              <button
                class="btn btn-outline-primary btn-sm pull-xs-right"
                :class="{
                  active: article.favorited,
                }"
                @click="onFavorite(article)"
                :disabled="article.favoriteDisabled"
              >
                <i class="ion-heart"></i> {{ article.favoritesCount }}
              </button>
            </div>
            <nuxt-link
              class="preview-link"
              :to="{
                name: 'article',
                params: {
                  slug: article.slug,
                },
              }"
            >
              <h1>{{ article.title }}</h1>
              <p>{{ article.description }}</p>
              <span>Read more...</span>
            </nuxt-link>
          </div>
        </div>

        <div class="col-md-3">
          <div class="sidebar box-height">
            <p>Popular Tags</p>

            <div class="tag-list">
              <nuxt-link
                :to="{
                  name: 'home',
                  query: {
                    tab: 'tag',
                    tag: item,
                  },
                }"
                class="tag-pill tag-default"
                v-for="item in tags"
                :key="item"
                >{{ item }}</nuxt-link
              >
            </div>
          </div>
        </div>

        <!-- 分页列表 -->
        <el-pagination
          background
          @current-change="handleCurrentChange"
          :current-page.sync="page"
          :page-size="limit"
          layout="total, prev, pager, next"
          :total="articlesCount"
        >
        </el-pagination>
        <!-- /分页列表 -->
      </div>
    </div>
  </div>
</template>

<script>
import { getArticles, getYourFeedArticles, addFavorite, deleteFavorite } from "@/api/article";
import { getTags } from "@/api/tag";
import { mapState } from "vuex";

export default {
  name: "HomeIndex",
  async asyncData({ query }) {
    const page = Number.parseInt(query.page || 1);
    const limit = 10;
    const tab = query.tab || "global_feed";
    const tag = query.tag;

    const loadArticles = tab === "global_feed" ? getArticles : getYourFeedArticles;

    const [articleRes, tagRes] = await Promise.all([
      loadArticles({
        limit,
        offset: (page - 1) * limit,
        tag,
      }),
      getTags(),
    ]);

    const { articles, articlesCount } = articleRes.data;
    const { tags } = tagRes.data;

    articles.forEach((article) => (article.favoriteDisabled = false));

    return {
      articles, // 文章列表
      articlesCount, // 文章总数
      tags, // 标签列表
      limit, // 每页大小
      page, // 页码
      tab, // 选项卡
      tag, // 数据标签
    };
  },
  watchQuery: ["page", "tag", "tab"],

  computed: {
    ...mapState(["user"]),
  },

  methods: {
    async onFavorite(article) {
      article.favoriteDisabled = true;
      if (article.favorited) {
        // 取消点赞
        await deleteFavorite(article.slug);
        article.favorited = false;
        article.favoritesCount += -1;
      } else {
        // 添加点赞
        await addFavorite(article.slug);
        article.favorited = true;
        article.favoritesCount += 1;
      }
      article.favoriteDisabled = false;
    },
    // 分页切换
    handleCurrentChange(page) {
      this.$router.push({
        name: "home",
        query: {
          page,
          tag: this.$route.query.tag,
          tab: this.tab,
        },
      });
    },
  },
};
</script>

<style scoped>
.box-height {
  max-height: 1260px;
  overflow-x: hidden;
}
.box-height::-webkit-scrollbar {
  display: none;
}
</style>
